The invention relates to a system for balancing upright piano key mechanisms, which is adapted to make said mechanisms more closely resemble those of grand pianos as to respondence.
It is known that at present there is a great difference of performance between grand or horizontal pianos and upright pianos, particularly for an accomplished and demanding pianist.
This difference is due to the fact that in grand pianos the key is balanced with respect to the balance rail pin by the weight of the wippen and its related hammer on one part and by the weight of the balancing leads on the other part, whereby the pianist operates the keys solely with the force of his fingers, creating a respondence between keys and strings which cannot be found in upright pianos.
Upright pianos, even those with the most advanced mechanisms, such as the Renner ones or the like, do not allow said respondence, because the wippen acting on the key weighs very light on it, whereby the best solution adopted so far in order to enable the pianist to play has been to place a downweight, consisting of a lead counterweight, on a portion of the key close to the wippen. In this way the key has no balance of forces and, as a result of this, the pianist must overcome this counterweight with the touch of his fingers in order to act on the strings through the piano key actions.
In other words, there is no direct respondence between the touch of the pianist and the striking, whereby an accomplished and demanding pianist will hardly find satisfaction in playing an upright piano.